Process for producing finely divided sulfur



Aug. 26, 1952 s. c. cARNEY PROCESS FOR PRODUCING FINELY DIVIDED SULFUR Filed May 23, 1949 muP mI CARNEY A T TORNE rs Patented Aug. 26, 1 952 OFF I CET DIVIDED SULFUR Samuel C. Carney, Bartlesville, kla., assignor to i Phillips Petroleum Company, a. corporation of Delaware Application May 23, 1949, Serial No. 94,850

This invention relates to a method of processingsulphur. In one of its more specific aspects itrelates to a method of producing finely divided sulphur. In another of its more specific aspects it relates to a method of producing finely divided sulphur by the dispersion of low viscosity molten sulphur.

j Sulphur has long been used in various manufacturing and industrial processes. In many industries it is quite desirable to utilize the sulphur in a finely divided form. Conventional processes which have been devised for the production of finely divided sulphur are relatively expensive and inefiicient. An example of the expensive and inefficient method of producing finely divided su1- phur is the production of flowers of Sulphur, which is a batch process. It is well known that batch operation is relatively more expensive and inefi'icient than continuous processes. Finely divided sulphur is also produced by grinding or milling solidified masses of sulphur. That type of operation requires expensive machinery and considerable power consumption.

Broadly speaking, this invention comprises the atomization of low viscosity molten sulphur into a heated normally gaseous hydrocarbon stream. The resulting sulphur-gas stream is cooled by the fine dispersion of a relatively cool fluid in the sulphur-gas stream. The atomized sulphur, when socooled, is solidified and is removed from the gas stream by electrical precipitation. Production of finely divided sulphur in this manner may be carried on very efficiently as compared to conventional methods of producing such finely divided sulphur material.

An object of this invention is to provide a method for producing finely divided sulphur. Another object of this invention is to produce finely divided sulphur from a low viscosity liquid phase. Another object of this invention is to provide a low temperature process for the production of finely divided sulphur. Another object of the invention is to provide an improved method for producing insoluble sulphur. Another object of the invention is to produce an efficient method for producing finelydivided sulphur. Other and be obtained upon reference to the accompanying "drawing which is a diagrammatic representation -of an apparatus and flow plan which is utilized in the process of this invention.

9 Referring particularly to the drawing, tank H is provided so as to receive crude sulphur from 12 Claims. (01. 23-224) conveyor conduit [2 which communicates between tank II and a sulphur supply sourcanot shown. Heater I3 is provided adjacent the lower portion of tank II and provides heat 'forjthe purpose of melting the crude sulphurin tank I I. The molten'sulphur is removed from tank I I by means of conduit II which has pump l5 positioned therein for the purpose of supplying the necessary pressure to movethe' molten sulphur from tank H to tank I6. Tank I6 ispositioned within furnace l1 and is heated within furnace I! by burning fuel which is supplied to furnace i1 through fuel inlet conduit 18. Eiliuent materials are removed from furnace'll through stack l9. Normally gaseous hydrocarbon material is conveyed from a hydrocarbonsdurce. not shown, by means of conduit 2|, through compressor 22 positioned therein, to-tank IS." The molten sulphur within tank I6 is placed under a pressure of at least 75 pounds and preferably under a pressure of at least 100 pounds per square inch. The molten sulphur within tank 16 is heated to a temperature at which its viscosity'is quite low. y

The low viscosity molten-.sulphuris removed from tank [6 through conduit 23' and is'passe'd into header member 24 whichat least partially surrounds conduit 25. Conduit 25 is provided with conduit 26 having valve 21 positioned therein. Conduit 26 may be utilized as an inlet or, an

outlet conduit. Normally gaseoushydrocarbon material is injected into line 25 through con- *duit 26 and is conveyed by conduit 25 to compressor 28, in which the pressure of the hydrocarbon material within line 25 is raised to such a point that the pressure energy can. be converted to high velocity. Heater 29 is provided in conduit 25, preferably at a point downstream of compressor 28. The hydrocarbon material is heated in heater 29 so as to raise the temperature of the hydrocarbon material to a temperature above the melting point of sulphur, but preferably not materially above the temperature of the molten sulphur. The heated gaseous hydrocarbon material is passed at a high velocity which is sufiicient to produce turbulent flow, i. e., ;a Reynolds number of about 3000 or greater.

through the conduit section 25 which is 'surfrom a source not shown is conveyed to header member 3| throughconduit member 32. The

cooling fluid is injected into conduit 25 as a fine spray in sufiicient volume to cool the sulphurgas stream and to chill the finely dispersed sulphur material therein. The sulphur-gas stream is passed through an electrical precipitator 33, such as a Cottrell precipitator, in which finely divided sulphur material which has been solidified by the cooling action of the cooling fluid stream is removed from the gas stream. The: finely divided sulphur material is removed from the bottom of precipitator 33 through conduit member 34.

A liquefied normally gaseous hydrocarbon, such as butane or propane, is very satisfactory for utilization as the cooling fluid. In some situations, however, I utilize water as the coolant. When water is used, it is desirable to remove as much of the water as possible from the gaseous hydrocarbon stream before it is returned to the atomization point. Cooler 35 is provided in conduit Z5 downstream of electrical precipitator 33. The hydrocarbon stream is passed through cooler 35 wherein it is cooled so as to condense water vapors therein. Drop-out chamber 36 is provided'in conduit downstream of cooler for the purpose. of removing condensed water from thehormally'gaseous hydrocarbon stream. The gas. stream is then recycled to compressor 28 where it once. again passes through the above described cycle. Whena normally gaseous hydrocarbon is. utilized as the cooling medium, the same hydrocarbon material is utilized as the atomization or carrier I stream. in conduit 25. When normally gaseous hydrocarbon is added as a. cooling fluid it is necessary to remove a portion. of the gas from conduit 25. A portion of the gas may be removed from conduit 25 through "conduit 3.! and valve 38 and passed to conduit Z-lasa. portion of thepressurizing gas for tank 16. ,The pressurizing gas is preferably added to the lower portion of tank is so as to entrain as much 'aspossibleof'the' gaseous material inthe molten's'ulphur. The portion of the entrained-gas aids in. the; atomization of. the liquid sulphur materialfupod injection into the dispersing e m-4 r r Sulphur material which is heated to its lowest viscosity is easily dispersed by the atomization reaches a low viscosity. In other details, the proc- I ess of this invention remains the same. The insoluble sulphur, well known as amorphous sulphur, tends to revert to the soluble form of sulphur at low storage temperatures. Such re version is greatly increased when the sulphur material is contacted with water before it solidifies. For thatreason, water is generally not utilized as the cooling fluid in the production of insoluble finely divided sulphur. The reversion of the insoluble form of sulphur to the soluble form is greatly retarded by contacting the sulphur with a halogen or halogen providing material. The halogens which are suitably utilized for this stabilization step are chlorine and bromine. The chlorine and bromine tend to remove small amounts of water from the sulphur and in that manner slow the reversion of the insoluble material. Ordinarily it is not necessary to utilize over 1 per cent by weight of the halogen in the atomizing gas.

When the amount of gaseous hydrocarbon within line 25 becomes too great, a furtherpo'rtion. of the hydrocarbon material is removed through conduit 25.' The removed hydrocarbon I may be passed through carbon disulphide to reanddispersing stepsof this invention. The par- I ticlesoffinely divided. sulphur which are formed I generally, range inflsize. below three microns. Finely divided sulphurmateriallmay be produced by the methodof this invention at a relatively low temperature. When heated to a temperature between. 285'?" F. and 316 F. the sulphur material reachesaviscosity of below e'ightcenti- .poises. The sulphur material is preferably heated to a temperatureof between 295 F. and 310 F. at. whicha first. minimum sulphur viscosity is obtained atv the low. temperatures. In such a state; the liquidinaterial .is easily atomizedand dispersed by'the action-ofthe high pressure gas stream flowing rapidly past the jet injection points which are provided for sulphur injection into that stream. 'Ihe sulphur material which is produced by this low temperaturemethodis inthe form of monoclinic sulphur. Monoclinic sulphur is.--,called:.soluble sulphur for it is soluble in carbon disulphide. In some instances it may be desirable to -produce finely divided sulphur which isvto a large extent-notsoluble in carbon disulphide. The processor this. invention is easily modified so as to also produce thattype-oi sulphur. It is necessary only to increas thetemper-ature of the sulphur within .tank' It to'a point move any .entrained sulphur material therefrom and then passed to the hydrocarbon supply source for storage. 0h the other hand, if the gaseous hydrocarbon materialis the same as that which is being utilized for the cooling fluid, which is ordinarily the case, the portion of gaseous mate'- rialwhich is removed from line 25 is passed to a compression zone, not shown, where it is compressed and cooled toa liquidstate and is utilized as the coolingfiui'd.

Much Of the pressuriz-ing gas which is added to the lower portion of tank- It is dis'so'lvedin the molten sulphurtherein. When the molten sulphur material is injected into the dispersing gas stream, the dissolved gas aids in the dispersalof finely divided'sulphur droplets and. also aids in cooling the finely dispersed sulphur droplets by the expansion and concomitant cooling of the gas which is released from solution.

The'finely divided sulphur droplets formedby atomization, of the molten sulphur are carried by the dispersing gas stream ,to the point of coolingwithout substantial vaporization of the liquid particles. The cooling fluid shock cools the sulphur'in a liquid state so-as to solidify the sulphur from that-liquid state. V

Other and further modifications of this invention will be apparent to'those skilled in the art upon study of this disclosure. Such modifications are believed to be within the spirit and the scope of the disclosure of this invention.

- I claim:

l. A process for the production offinely' divided sulphur which comprises the steps of placing low viscosity molten sulphur at a-temperaturebelow itsboiling point under operating conditions, under pressure; injecting said sulphur as aline; liquid spray of highly dispersed droplets-- directly into a high velocity gas stream which "is at a' temperature abovethemelting point of sulphur and which is flowing at a Reynolds number ofat least 3000 ;injecting a-eooleriluidinto said sulphur-gas stream so aswtocool said sulphur-gas stream and to chill an solidify said highlydis persed droplets of sulphur; and separating said sulphur from the other materials. in said-stream.

2. A process for the production of finely divided sulphur which comprises the steps of heating sulphur to between 285 F. and 316 F., whereby said sulphur is converted to a molten state; placing said molten sulphur under a pressure of at least 75 pounds per square inch; injecting said sulphur as a fine liquid spray of highly dispersed droplets directly into a stream of normally gaseous hydrocarbon material flowing at a Reynolds number of at least 3000, said gas being at a temperature above the melting point of sulphur; injecting a cooler fluid into said sulphur containing-gas stream so as to cool said sulphur-gas stream and to crystallize said highly dispersed droplets of sulphur; and separating said sulphur from the other materials in said stream.

3. The process of claim 2, wherein said cooler fluid is water. I

4. A process for the production of finely divided sulphur which comprises the steps of heating sulphur to between 285 F. and 316 F., whereby said sulphur is converted to a molten state; injecting a first portion of a normally gaseous hydrocarbon material into said molten sulphur so as to disperse at least a portion of said hydrocarbon material therein and to place said sulphur under a pressure of at least 100 pounds per square inch; injecting said sulphur-hydrocarbon mixture as a fine liquid spray of highly dispersed sulphur droplets directly into a stream of a second portion of said normally gaseous hydrocarbon material flowing at a Reynolds number of at least 3000, said second gas portion being at substantially the temperature of said molten sulphur; injecting a third portion of said normally gaseous hydrocarbon material into said sulphur-containing hydrocarbon gas stream as a fine liquid spray so as to cool said sulphur-gas stream and to crystallize said highly dispersed droplets of sulphur; and separating said sulphur crystals from the other materials in said stream.

5. A process for the production of finely divided sulphur which comprises the steps of heating sulphur to between 295 F. and 310 F., whereby said sulphur is converted to a low viscosity molten state; injecting a first portion of a normally gaseous hydrocarbon material into said molten sulphur so as to disperse at least a portion of said hydrocarbon material therein and to place said sulphur under a pressure of at least 100 pounds per square inch; injecting said sulphur-hydrocarbon mixture as a fine liquid spray of highly dispersed sulphur drop ets directly into a stream of a second portion of said normally gaseous hydrocarbon material flowing at a Reynolds number of at least 3000, said second gas portion being at substantially the temperature of said molten sulphur; injecting a third portion of said normally gaseous hydrocarbon material into said sulphur-containing hydrocarbon gas stream as a fine liquid spray so as to cool said sulphur-gas stream and to crystallize said highly dispersed droplets of sulphur; and separating said sulphur crystals from the other materials in said stream.

6. The process of claim 5, wherein said sulphurcontaining gas stream is passed through an electrical precipitator wherein said sulphur crystals are separated from said gas stream.

7. The process of claim 5, wherein said second portion of said gas stream contains a material which supplies to said sulphur-containing stream a small amount of a halogen selected from the group consisting of chlorine and bromine.

8. Th process of claim 5, wherein at least a portion of said first portion of normally gaseous hydrocarbon material is dissolved in said molten sulphur.

9. A process for the production of finely divided sulphur which comprises the steps of heating sulphur to between 285 F. and 316 F., whereby said sulphur is converted to a low viscosity molten state; placing said molten sulphur under a pressure of at least 75 pounds per square inch; in jecting said sulphur as a fine liquid spray of high 1y dispersed droplets directly into a stream of normally gaseous hydrocarbon material. flowing at a Reynolds number of at least 3000, said gas being at substantially the temperature of said molten sulphur; injecting a fine spray of water into said sulphurcontaining-gas stream so as to cool said sulphur-gas stream and to crystallize said highly dispersed droplets of sulphur; separating unvaporized water from said stream; and passin said sulphur-gas stream through an electrical precipitator so as to precipitate said sulphur crystals therefrom.

10. A process for the production of finely divided sulphur which comprises the steps of heating sulphur to between 680 F. and the boiling point of said sulphur under operating conditions, whereby said sulphur is converted to a low viscosity molten state; placing said molten sulphur under a pressure of at least 75 pounds per square inch; injecting said sulphur as a fine liquid spray of highly dispersed droplets directly into a stream of a first portion of normally gaseous hydrocarhon material flowing at a Reynolds number of at least 3000, said gas being at a temperature above the melting point of sulphur; injecting a second portion of said normally gaseous hydrocarbon material into said sulphur containing-gas stream as a fine liquid spray so as to shock cool said sulphur-gas stream and to chill and solidify said highly dispersed droplets of sulphur; and separating said sulphur from the other materials in said stream.

, 11. The process of claim 10, wherein said second portion of said gas stream contains a material which supplies to said sulphur-containing stream a small amount of a halogen selected from the group consisting of chlorine and bromine.

12. A process for the production of finely divided sulphur which comprises the steps of placing low viscosity molten sulphur at a temperature below its boiling point under operating conditions; under pressure of at least 75 pounds per square inch; injecting said sulphur as a fine spray directly into a high velocity gas stream which is at a temperature above the melting point of sulphur and which is flowing at a Reynolds number of at least 3000; injecting a cooler fluid into said sulphur-gas stream so as to cool said sulphur-gas stream and to chill and solidify said sulphur; and separating said sulphur from the other materials in said stream.

SAMUEL C. CARNEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 359,164 Lightner Mar. 8, 1887 1,859,992 Seil May 24, 1932 1,992,611 Grindrod Feb. 26, 1935 2,330,934 Thacker Oct. 5, 1943 2,413,714 Keeling Jan. 7, 1947 2,460,365 Schallis Feb. 1, 1949 

1. A PROCESS FOR THE PRODUCTION OF FINELY DIVIDED SULPHUR WHICH COMPRISES THE STEPS OF PLACING LOW VISCOSITY MOLTEN SULPHUR AT A TEMPERATURE BELOW ITS BOILING POINT UNDER OPERATING CONDITIONS, UNDER PRESSURE; INJECTING SAID SULPHUR AS A FINE LIQUID SPRAY OF HIGHLY DISPERSED DROPLETS DIRECTLY INTO A HIGH VELOCITY GAS STREAM WHICH IS AT A TEMPERATURE ABOVE THE MELTING POINT OF SULPHUR AND WHICH IS FLOWING AT A REYNOLDS NUMBER OF AT LEAST 3000; INJECTING A COOLER FLUID INTO SAID SULPHUR-GAS STREAM SO AS TO COOL SAID SULPHUR-GAS STREAM AND TO CHILL AND SOLIDIFY SAID HIGHLY DISPERSED DROPLETS OF SULPHUR; AND SEPARATING SAID SULPHUR FROM THE OTHER MATERIALS IN SAID STREAM. 